The present disclosure relates to an encoder spacer for a spindle motor and an encoder assembly including the same.
A spindle motor performs the function of rotating a disk to enable an optical pickup which linearly reciprocates in an Optical Disk Drive (ODD) to read data recorded on the disk.
With the technical advancement of an Optical Disk Drive (ODD), a new ODD has been developed and used. The new ODD has a light scribe function of forming a desired design on the surface of a Compact Disk (CD) or a Digital Versatile Disk (DVD) by using laser.
In order to reproduce information recorded on a disk or record information on the disk, the disk must be rotated at a high speed of approximately 5,400 rpm. In contrast, in order to form a design on the surface of the disk, the disk must be rotated at a low speed of approximately 40 rpm in a state in which the disk is mounted on a turntable by turning over the disk.
To this end, an encoder may be installed at the spindle motor in order to determine if the disk rotates at a proper speed when forming the design on the surface of the disk.
FIG. 1 is a cross-sectional view illustrating configuration of the conventional spindle motor and FIG. 2 is an exploded perspective view illustrating an encoder assembly of FIG. 1.
Referring to FIG. 1, a turntable 11 mounted with a disk 50 is provided, and an upside-down disk 50 is mounted on the turntable 11 to allow an upper surface of the disk 50 attached with a label to face downward when a design is formed on the surface of the disk 50.
A rim-shaped recognition mark 53 is formed on a certain portion of the disk 50 positioned at a periphery of the turntable 11, i.e., an upper surface portion of the disk 50 on which the design is formed, and an encoder 21 is installed on a main Printed Circuit Board (PCB 13) underneath the recognition mark 53. The encoder 21 detects the recognition mark 53 to determine if the disk rotates at a proper speed.
In more detail, since the encoder 21 is manufactured in a small size, a support member, e.g., a spacer, can be interposed between the encoder 21 and the disk 50 in order to allow a gap between the encoder 21 and the disk 50 to be within a predetermined range.
Referring to FIG. 2, a spacer 23 is integrally connected by insert mold injection to a terminal 26 connected to the main PCB 13 and a terminal 25 connected to an auxiliary PCB 27, and the auxiliary PCB 27 mounted with the encoder 21 is installed on an upper surface of the spacer 23.
The auxiliary PCB 27 is formed with a via hole 27a through which the terminal 25 of the spacer 23 can pass, and is fixed to an upper surface of the spacer 23 by way of soldering, while the terminal 26 is soldered to the main PCB 13.
Generally, a spindle motor can be categorized into two types based on a height of the motor, that is, a super slim spindle motor and a slim spindle motor, where each of the two motors must have a different assembled encoder height due to a different turntable height.
However, there is a disadvantage in the configuration thus mentioned in that parts cannot be commonly used due to the fact the height of injection-molded spacer must be differently designed. Another disadvantage is that it is difficult to manufacture a spacer due to a very low height of the turntable for the super slim spindle motor.